Photographic apparatus to spread processing fluid in uniform layer

ABSTRACT

A pair of spreader elements in photographic apparatus to effect the spreading of a processing fluid as a layer between two sheets of material as such sheets are advanced therebetween. The spreader elements are provided with a pair of facing surfaces which exert a compressive force on the sheet materials. At least one of these facing surfaces is provided with a recessed portion adjacent each of its ends to initially provide selected increased thicknesses of processing fluid in the fluid layer formed immediately thereunder. In a preferred embodiment, the spreader elements are pivotally mounted for movement into and out of juxtaposition, with one of such elements being formed of a resiliently flexible material having a concavity initially provided in its facing surface and extending substantially thereacross. When such pivotally mounted spreader elements are disposed in their operative position, a force is directed centrally against the resiliently flexible member to deform its facing surface whereby a small concavity is provided adjacent each of its ends.

ted States Patent [191 [1 1 3,7429834 Thoenen [451 July 3, 1973 [54] PHOTOGRAPH: APPARATUS TO Primary Examiner-Samuel S. Matthews SPREAD PROCESSING FLUID IN Assistant Examiner-Richard M. Sheer UNIFORM LAYER Attorney-Brown and Mikulka, William D. Roberson [75] Inventor Earl R Thoenen Newburyport and Robert Berger Mass- 57 ABSTRACT [73] Asslgnee: Polaroid corponmon Cambridge A pair of spreader elements in photographic apparatus Massto effect the spreading of a processing fluid as a layer [22] Fil d; J 26, 1970 between two sheets of material as such sheets are ad- 21 vanced therebetween. The spreader elements are pro- 1 Appl' 50341 vided with a pair of facing surfaces which exert a compressive force on the sheet materials. At least one of 521 US. Cl ..95/13, 95/89 these facing Surfaces is Provided h recessed P9 51 Int. Cl. ..G03b 17/50 i glq g endsfto mmally g qg q 58 Field of Search ..95 13, 89 Se ec e Increase c 0 Processmg 1 I the fluid layer formed immediately thereunder. In a [56] References Cited preferred embodiment, the spreader elements are plvotally mounted for movement into and out of JLlX- UNITED STATES PATENTS taposition, with one of such elements being formed of a resiliently flexible material having a concavity inigl fll tially provided in its facing surface and extending sub- 3132572 me i stantially thereacross. When such pivotally mounted 5/1964 Downey l 3 spreader elements are disposed in their operative posi- 4 7 tion, a force is directed centrally against the resiliently flexible member to deform its facing surface whereby a small concavity is provided adjacent each of its ends.

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PHOTOGRAPHIC APPARATUS TO SPREAD PROQESSING FLUID IN UNIFORM LAYER BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to photography and, more particularly, to improved processing fluid spreader elements.

'tially be releasably stored in a rupturable pod or container attached to one of such photographic sheets. As the assembly, comprising such sheets and pod, is advanced between the spreader elements, those members exert a compressive force thereon that first ruptures the pod and subsequently spreads the fluid released therefrom as a layer between the superposed sheets. The spreader elements themselves may, for instance, comprise either a pair of rollers, one roller and a rigid nonrolling member, or a pair of rigid nonrolling members.

The fluid-spreading process is a critical consideration in producing high quality photographic prints in cameras of this type. Much effort was required to develop, engineer, and manufacture the film units and spreader elements employed in the self-developing cameras currently being marketed. The quality of the finished print provided by these systems is directly related to the nature of the fluid coating applied to the photographic sheets. As is well known, such cameras are capable of producing photographic prints generally most pleasing to the public.

However, an amount of red bar or red framing can occur in the photographs produced by cameras of the self-developing type which, to some degree, detracts from the overall quality of the finished print. These terms, i.e., red bar and red framing, are generally employed to refer to areas in a color print adjacent one or more of its borders which have a disproportionate amount of red tones. In black-and-white prints, the same characteristic streaking appears in the form of disproportionate white areas adjacent one or more borders of the print. It has been determined that in both cases this undesirable eflect results from such areas of the photograph being underdeveloped during the processing operation.

One of the objects of this invention, therefore, is to provide improved photographic apparatus for spreading a processing fluid as a layer between sheets of material.

Another primary object of this invention is to provide improved fluid-spreading apparatus for use in connection with diffusion-transfer photographic processes which facilitates the production of a uniformly developed viewable image.

An important object of this invention is to provide improved photographic apparatus which effects the spreading of a layer of processing fluid between a pair of sheet materials wherein the thickness of such layer is initially increased in sections thereof adjacent opposite edges of such materials.

A still further object of this invention is to provide a relatively simple and inexpensive spreader system for use in photographic apparatus comprising a pair of pivotally connected spreader elements having juxtaposed facing surfaces when disposed in their operative position and wherein at least one of such surfaces is automatically deformed at such times to provide a concavity adjacent each opposite end thereof.

SUMMARY OF THE INVENTION Self-developing type cameras generally employ a pair of elongated spreader elements to distribute processing fluid as a layer between a photosensitive image-recording sheet and an image-receiving sheet. Typically, such spreader elements may comprise a pair of rollers or a pair of rigid nonrolling members having facing surfaces adapted to contact the sheet materials as they are advanced therethrough in superposed relationship. In such systems, the layer of processing fluid as initially spread between the sheet materials by the spreader elements is of a substantially uniform thickness. It has been determined that, after the progressive sections of the assembly, comprising the two sheets with the uniform layer of fluid distributed therebetween, are advanced beyond the influence of the spreader elements, stress relief of the uniformly distributed fluid causes a certain amount of the fluid to be drawn away from areas adjacent each of the longitu-v dinal edges of the assembly. Thus, in the case of these prior art systems, the layer of processing fluid as finally formed between the two sheets of material, and, therefore, which exists therebetween during the major portion of the processing operation, is not of a uniform thickness. This situation can result in undeveloped areas of the final photograph adjacent its two longitudinal edges. The present invention is directed to a fluidspreading apparatus which improves the overall quality of the final print by assuring that the layer of processing fluid as disposed between the two sheets of material immediately after the sheets have advanced beyond the influence of the spreader elements is of a uniform thickness. Such arrangement facilitates the uniform development of a visible image from the latent image recorded during the exposure operation.

In this connection, the spreader elements are configured to initially form a layer of the processing fluid between the two sheets of material having an increased thickness adjacent each of the opposite ends of the spreader elements. The illustrated preferred embodiment of this invention is adapted for use with a film unit comprising a first sheet having substantial thickness and rigidity and a second sheet formed of a relatively thin and flexible, and therefore deformable,material. Further, in the preferred embodiment, the spreader members are of the rigid nonrolling type being pivotally connected together for selective displacement between a first inoperative position and a second operative position. In such latter position, they present a pair of juxtaposed sheet-contacting, pressure-generating surfaces. In this arrangement, the spreader element adapted to contact the relatively deformable sheet of material has its facing surface initially provided with a recessed portion extending substantially across its entire length. A flexible rod serves to pivotally connect the two spreader elements together and to exert a force centrally against the aforementioned flexible spreader ele-' ment when they are disposed in their operative position. This force is such as to deform the facing surface of the flexible element to provide a concavity therein adjacent each of its ends.

Thus, when these two pivotally connected spreader elements are disposed in their operative position, their facing surfaces are generally parallel except in the vicinity of the aforementioned concavities. As the sheets of material are advanced between the spreader elements, the fluid layer initially distributed between these sheets is of an increased thickness adjacent the longitudinal edges of their image-receiving components, i.e., at locations spaced from their longitudinal centerlines and either at the longitudinal edge portions of their image-receiving components or not far distant from the longitudinal edges of those components. However, as the assembly, comprising the two sheets of material with the layer of fluid disposed therebetween, is advanced beyond the influence of the spreader elements, stress relief within the fluid layer draws processing fluid from the sections thereof adjacent its two edges causing the fluid layer to assume a substantially uniform thickness. As indicated, such an arrangement results in a uniformly developed finished print.

BRIEF DESCRIPTION OF THE DRAWINGS The novel features that are .considered characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of the preferred embodiments when read in connection with the accompanying drawings wherein like numbers have been employed in the difierent figures to denote the same parts and wherein:

FIG. 1 is a diagrammatic perspective view of a selfdeveloping camera embodying features of this invention;

FIG. 2 is an exploded diagrammatic perspective view of the fluid-spreading apparatus employed in the camera illustrated in FIG. 1;

FIG. 3 is a fragmentary sectional view taken generally along line 3-3 of FIG. 2 illustrating the spreader elements at such time as they are disposed in their inoperative position;

FIG. 4 is a view similar to FIG. 3 illustrating the spreader elements at such time as they are disposed in their operative position;

FIG. 5 is a fragmentary diagrammatic view in profile illustrating a pair of prior art spreader elements having a film unit disposed therebetween;

FIG. 8 is a diagrammatic lateral sectional view of the film unit illustrated in FIG. 7 immediately after it has FIG. 6 is a diagrammatic lateral sectional view of the 1 been advanced beyond the influence of the spreader elements;

FIG. 9 is a diagrammatic profile view of the imagereceiving sheet-contacting spreader element employed in the camera of FIG. 1 in its inoperative position;

FIG. 10 is a view of the spreader element illustrated in FIG. 9 in its operative position; and

FIG. 11 is a fragmentary diagrammatic perspective view of an alternate embodiment of a fluid-spreading system incorporating features of the present invention.

DESCRIPTION OF A PREFERRED EMBODIMENT In its first illustrated embodiment, the present invention is depicted as forming part of a self-developing camera 10. As shown in FIG. 1, this camera 10 is basically constituted by a main camera body 12 to which a back body member 14 is pivotally connected. When the back body member 14 is disposed in its opened position with respect to the main camera body 12, access is provided into the interior of the camera 10 for the purpose of loading the camera 10 with a film pack (not shown) containing a sufficient quantity of photographic materials to produce a plurality of reflective photographic prints. These film packs may, for exam ple, be identical to those manufactured by the Polaroid Corporation of Cambridge, Massachusetts, and

. identified as Polacolor Land Film Type 108. As such, in

order to produce each reflective print, the film pack includes a relatively thick stiff sheet of image-receiving material, to which is connected a rupturable pod or container of processing fluid, and a relatively thin flexible, and therefore deformable, sheet of photosensitive image-recording material.

Forming part of the main camera body 12 is a lens and shutter housing 16 which may take a conventional form. This housing 16 is mounted at the outer end of an extensible bellows 18 that is provided with a suitable erecting mechanism 20. Attached at one side of the main camera body 12 is a rangefinder-viewfinder 22 that is shown in phantom so as not to obstruct the view of other portions of the camera 10. A processing fluidspreading device 24 incorporating the features of the present invention is removably retained within the back body member 14 adjacent its free end. After the film pack has been loaded into the camera 10, the cameras back body member 14 may be pivoted to its closed position wherein it cooperates with the main camera body 12 to form a light-sealed chamber adapted to facilitate film exposure operations.

Reference is now made to FIGS. 2, 3, and 4 of the drawings which more clearly depict the nature of the processing fluid-spreading device 24. As shown therein, this device 24 basically comprises three components, i.e., a first spreader element 26, a second spreader element 28, and an elongated rod 30, the lastmentioned component serving, in part, to pivotally connect the first two stated elements, one to the other. Each of these spreader elements 26 and 28 may, for instance, advantageously be fabricated from a single sheet of metal such as stainless steel or aluminum in mately a 90 angle to define a sheet-contacting facing surface 36. Provided across the platform 34 adjacent the facing surface 36 is a relieved zone 38, the purpose of which will be subsequently explained herein. A spring-type member 41 provided with up-turned flanges 42, 44, and 46 extends from the end of the platform 34 furthermost disposed from the facing surface 36. Extending upwardly from the platform 34, adjacent the opposite ends of the facing surface 36, are a pair of flanges 48 and 50 respectively provided with inwardly directed tabs 52 and 54 and outwardly depending tabs 56 and 58. When the fluid-spreading device 24 is inserted into the camera and seated against the cameras back body member 14, the flange 46, extending from the spreader element 26, is engaged by a clip 60 (see FIG. 1) which serves to releasably retain the device 24 in the camera 10. In this connection, when the camera 10 is loaded with one of the aforementioned film packs and its back body member 14 is closed against the cameras main body 12, portions of the film pack press against the flanges 42 and 44 to securely lock the flange 46 in the clip 60. Also, at such times, members (not shown) formed on the main camera body 12 engage the tabs 56 and 58 of the spreading device 24 to further restrict or limit movement of that device within the camera 10. Simultaneously, these tabs 56 and 58 serve to align the spreading device 24 laterally within the back body member 14.

The first spreader member element 26 includes a flat section 64 from which a section 66 extends at approximately a 45 angle to define a sheet-contacting facing surface 68. Also extending from the same side of the flat section 64 is a pin 70 positioned midway between the ends of the spreader element 26. The lateral ends of section 64 respectively terminate in ears 72 and 74 provided with elongated apertures 76 and 78. In order to pivotally connect the spreader elements 26 and 28 one to the other, the elongated apertures 76 and 78 of the first spreader member are first respectively aligned with circular apertures 80 and 82 of the second spreader members flanges 48 and 50. Then the elongated rod 30 is slid through these apertures 76, 78, 80, and 82 so that its center portion is disposed on the side of the pin 70 furthermost removed from the spreader element 28 as viewed in FIG. 2. It will thus be appreciated that the spreader element 26 may be pivoted with respect to the element 28 between an inoperative position as shown in FIG. 3 of the drawings and an operative position as shown in FIG. 4.

When the spreader elements 26 and 28 are disposed in their inoperative positions illustrated in FIG. 3, their sheet-contacting facing surfaces 36 and 68 are readily accessible for inspection and/or cleaning purposes. The section 66 of the spreader element 26 terminates in specially configured end portions 84 and 86 which respectively include sections 88 and 90 adapted to engage spacers 92 and 94 extending from the platform 34 as the element 26 is pivoted into its operative position shown in FIG. 4. In reaching its operative position, the spacers 92 and 94 establish a predetermined minimum spacing between the facing surfaces 36 and 68 of the spreader elements 26 and 28. In this connection, the rod 30 is stressed or bowed over the pin 70, and the configuration of the elongated apertures 76 and 78, in which slots the opposite ends of the rod are positioned,

pemiits a certain amount of movement of the spreader element 26 in the direction away from the spreader element 28. Thus, at such times, the facing surfaces 36 and 68 define a pressure-generating gap 96 between the spreader elements 26 and 28, such gap having a minimum dimension as determined by the spacers 92 and 94. It will be recognized that this arrangement facilitates the introduction of materials of varying thicknesses between the facing surfaces 36 and 68, which surfaces may thereafter exert a compressive force on such materials under the influence of the flexible rod 30. The other sections 98 and 100, respectively, of the end portions 84 and 86 are configured to engage the longitudinal edges of a film unit being advanced through the gap 96 against the platform 34 in front of the gap so as to preclude escape of processing fluid from between the sheet materials comprising such film unit. In this connection, a typical such film unit includes a rupturable pod of processing fluid attached to one of its photographic sheets. The relieved zone 38 of the platform 34 allows a portion of the pod to extend before its rupture thereby facilitating proper movement of the film unit through the pressure-generating gap 96.

When the processing fluid-spreading device 24 is mounted in the cameras back body member 14 and its spreader elements 26 and 28 are disposed in their operative positions, the pressure gap 96 defined by the facing surfaces 36 and 68 is aligned with an elongated exit port (not shown) formed through the adjacent wall 104 (see FIG. 1) of the back body member. Also, when the back body member 14 is closed against the main camera body 12, the edge of the wall 104, in conjunction with the slotted section 106 of the main camera body 12, provides additional access into the camera 10. As is well known, when a film pack of the type indicated is mounted in the camera 10 and the back body member 14 thereof closed thereover, a tab attached to the first film unit extends through the opening provided by the slotted section 106. By drawing on that tab, the first photosensitive image-recording sheet is made available for exposure and a leader attached to the film unit is advanced into the pressure-generating gap 96 of the fluid-spreading device 24 so as to protrude through the adjacent elongated exit port of the cameras back body member 14. After the exposure operation has been effected, the operator may pull on the portion of this leader accessible exteriorly of the camera 10 to advance the film unit, comprising the exposed imagerecording sheet, an image-receiving sheet, and a rupturable pod of processing fluid, through the pressuregenerating gap 96 of spreader elements 26 and 28. During such operation, the pod is ruptured and the processing fluid initially retained therein is spread by the elements 26 and 28 as a layer between the photographic sheets.

The self-developing camera system so far described constitutes prior art with respect to the present invention and is substantially similar to that described in the copending application Ser. No. 837,422, entitled Liquid Spreader filed on June 30, 1969, by Vaito K. Eloranta.

Referring now to FIG. 5 of the drawings, there is diagrammatically shown therein a cross-sectionof a typical film unit 108 as it passes between the sheet-contacting facing surfaces 110 and 112 that define a pressuregenerating gap between prior art spreader elements 114 and 116 of a rigid nonrolling type. The thicknesses of the various components depicted in FIG. 5 have been exaggerated for purposes of clarity. Extending from the spreader element 116 toward the spreader element 114 are a pair of spacers 118 and 120 that establish the minimum spacing between those elements. The film unit 108 comprises a relatively thick, stifi image-receiving sheet 122, to which framing members 124 and masks 126 are attached, and a relatively thin, flexible, deformable image-recording sheet 128. The spreader elements 114 and 116 effect the spreading of a processing fluid 130 in a layer between the image-receiving sheet 122 and the image-recording sheet 128 as those sheets move in superposition through the gap defined by the facing surfaces 1 l and 112.

FIG. 6 illustrates the section of the film unit 108 illustrated in FIG. of the drawings immediately after it has been advanced beyond the influence of the spreader elements 114 and 116. It has been determined that, at such time, the stress-relieving action that takes place within the polymeric processing fluid 130 causes quantities of such fluid to be withdrawn from sections of the film unit 108 spaced a slight distance from the respective longitudinal edges of that unit. This situation is shown in FIG. 6. In this fluid stress-relieving process, sections of the relatively thin and flexible imagerecording sheet 128 adjacent the respective longitudinal edges of that sheet deform inwardly of the film unit toward the image-receiving sheet 122. Therefore, although the prior art spreader elements 114 and 116 initially spread a layer of processing fluid 130 between the sheets 122 and 128 having a uniform thickness, subsequent stress relieving within the fluid produces sections of the fluid layer adjacent its respective longitudinal edges and closely spaced therefrom which are thinner than the remaining lateral section thereof. This situation produces fluid-starved or underdeveloped sections of the film unit resulting in red framing in color prints and disproportionately lighter areas in black-and-white prints. I

, To avoid such undesirable effects, the spreader elements 26 and 28 of the present invention initially distribute a layer of processing fluid 134 between the sheets of a film unit 109 having an increased thickness in each section 136 and 138 adjacent and closely spaced from its longitudinal edges (see FIG. 7). As shown in the last-stated figure of the drawings, when the spreader elements 26 and 28 are disposed in their operative positions, their facing surfaces, in profile, extend in generally parallel relationship except for a pair of recesses or concavities 140 and 142 formed in, and constituting discontinuities of, the facing surface 68 of the spreader element 26. It is these concavities 140 and 142 of the element 26 that permit a deformation of the flexible sheet 128 adjacent each of its lateral edges to provide the sections 136 and 138 of increased thickness in the layer of fluid 134.

The section of the film unit 109 shown in FIG. 7 of the drawings is depicted in FIG. 8 at such time as it has been advanced through the pressure-generating gap 96 a sufficient distance to be removed from the influence of the spreader members 26 and 28. It will be noted that, at such time, the layer of processing fluid 134 has assumed a substantially uniform thickness. More specifically, stress relief within the processing fluid 134 has drawn processing fluid from the sections 136 and 138 whereby the adjacent portions of the imagerecording sheet 128 have assumed an alignment generally parallel with the adjacent portions of the image-receiving sheet 122. Consequently, as the processing sequence continues, the sheets 122 and 128 are unifomily treated with the fluid 134 to produce an extremely high quality photographic print.

In the illustrated preferred embodiment of the invention, the spreader element 26 is initially formed of a flexible material with its sheet-contacting facing surface 36 being provided with a recessed portion 144 extending substantially thereacross (see FIG. 9). This arrangement constitutes the profile configuration of the facing surface 36 at such times as the spreader element 26 is disposed in its inoperative position as shown in FIG. 3 of the drawings. As the spreader element 26 is pivoted on the flexible rod 30 into its operative position as shown in FIG. 4 of the drawings, that rod exerts a force against the pin 70, which pin transfers such force to the spreader element 26 causing its sheet-contacting facing surface 36 to deform into the configuration depicted in both FIGS. 7 and 10 of the drawings. When the spreader element 26 is subsequently returned to its inoperative position with respect to the spreader element 28, its facing surface 36 resumes its initial configuration depicted in FIG. 9 of the drawings.

Certain dimensions have been indicated on FIG. 7 in order to impart a full understanding of the present invention. However, it is to be expressly understood that these dimensions are exemplary only and are not to be interpreted as restricting the scope of applicants invention in any manner.

DESCRIPTION OF AN ALTERNATE EMBODIMENT An alternate embodiment of this invention is illustrated in FIG. 11 of the drawings. In this alternate arrangement, the present invention has been incorporated into a processing fluid spreading device 146' that employs spreader elements of the. rolling type. As shown, a fluid-spreading device 146 comprises a first roller element 148 adapted to engage a relatively thin and flexible image-recording sheet 147 of a film unit 111, and a second roller element 150 adapted to engage a relatively thick and stiff image-receiving sheet 145 of that film unit. Provided at the opposite ends of the roller 148 are a pair of annular collars 152 and 154 which, when seated against the adjacent portion of the peripheral surface of the cylindrical roller 150, determine the minimum spacing, or pre-gap distance, between the sheet-contacting surfaces of the two rollers. In this connection, the roller 148 is mounted for rotation on a support 155 against which the coiled springs 156 and 158 act to continually urge the roller 148 toward the roller 150.

The sheet-contacting surfaces of the rollers 148 and 150 extend in substantially parallel alignment except for annular concavities 160 and 162 respectively provided in, and closely spaced from the opposite ends of, the former such sheet-contacting surface. It will be recognized that this arrangement functions in a manner similar to the first-described embodiment of this invention to initially provide an increased thickness of processing fluid 149 adjacent both longitudinal edges of a film unit as such film unit is progressively advanced between a pair of fluid-spreading elements. Subsequent stress relief within the layer of processing fluid 149 formed by the specially configured rollers 148 and 150 effect a redistribution of the fluid so that the layer assumes a substantially uniform thickness. At such time, the image-recording material 147 has assumed a substantially parallel relationship with respect to the image-receiving sheet 145.

Those familiar with the motion picture arts will readily appreciate the novel and highly unique advantages of this invention. Most importantly, a relative- 1y simple and inexpensive processing fluid spreading device is provided which effects the uniform development of photographic prints.

This invention may be practiced or embodied in still other ways without departing from the spirit or essential character thereof. For instance, in situations where the processing fluid is spread between a pair of sheet materials, both of which are readily deformable, concavities may be appropriately provided in the sheetcontacting facing surfaces of both fluid-spreading elements. It will also be obvious to those skilled in the art that this invention is equally applicable to many types of photographic processing fluid spreading systems other than those illustrated in the drawings of this specification. The embodiments described herein are therefore illustrative and not restrictive, the scope of the invention being indicated by the appended claims, and all variations which come within the meaning of the claims are intended to be embraced therein.

I claim:

1. Apparatus for rupturing a pod of processing fluid and for spreading such processing fluid as a layer between two sheets of material responsive to relative motion being effected between said apparatus and such sheets lengthwise of such sheets, at least one of such sheets including a component adapted to have a visible image formed in a section thereof having a given width, said apparatus comprising:

a pair of spreader elements each having a sheet contacting surface extending a distance at least equal in length to such section of such component;

means for mounting said spreader elements with their said sheet contacting surfaces in juxtaposition and disposed to exert a compressive force on such sheets over such section of such component as they are progressively drawn lengthwise therebetween in superposed relationship to first effeet the rupture of such pod of processing fluid and then to effect the spreading of such fluid in a layer between such sheets; and

means on at least one of said spreader elements for increasing the thickness of such layer of fluid spread between such sheets by said spreader elements along at least one longitudinal portion of such section of such component spaced from the longitudinal centerline of such component section and adjacent one longitudinal edge thereof, said last mentioned means including a recess in, and constituting a discontinuity of, said surface of said one spreader element adjacent such one longitudinal portion of such component section.

2. The invention of claim 1 wherein said recess comprises a concavity.

3. The invention of claim 1 wherein said last mentioned means includes a pair of recesses provided in, and constituting discontinuities of, said surface of said one spreader element respectively formed on said one spreader element spaced from the longitudinal centerline of such section of such component and positioned adjacent the longitudinal edges of such section of such component as such sheets are moved relative to said spreader elements.

4. The invention of claim 1 wherein such one sheet is relatively flexible with respect to the other of such sheets and said recess is formed in said surface of said spreader element adapted to engage said one sheet.

5. The invention of claim 1 wherein said spreader elements are of the substantially rigid non-rolling type.

6. The invention of claim 1 wherein at least one of said spreader elements comprises a roller.

7. The invention of claim 1 wherein said juxtaposed surfaces are substantially parallel except for the portions thereof adjacent said fluid thickness increasing means.

8. Apparatus for rupturing a pod of processing fluid and for spreading such processing fluid as a layer between two sheets of material responsive to relative motion being effected between said apparatus and such sheets lengthwise of such sheets, at least one of such sheets including a component adapted to have a visible image formed in a section thereof having a given width, said apparatus comprising:

a pair of spreader elements each having opposed ends and a sheet contacting surface extending a distance at least equal in length to such section of such component;

means for mounting said spreader elements with their said sheet contacting surfaces in juxtaposition and disposed to exert a compressive force on such sheets over such section of such component as they are progressively drawn lengthwise therebetween in superposed relationship to first effect the rupture of such pod of processing fluid and then to effect the spreading of such fluid in a layer between such sheets; and

means on at least one of said spreader elements for increasing the thickness of such layer of fluid spread between such sheets by said spreader elements along at least one longitudinal portion of such section of such component, said last mentioned means including a recess in, and constituting a discontinuity of, said surface of said one spreader element adjacent such one longitudinal portion of such component section and entirely positioned between the ends of the portion of said surface of said one spreader element adapted to extend across such section of such one sheet as such sheets pass between said spreader elements.

9. Apparatus for rupturing a pod of processing fluid and for spreading such processing fluid as a layer between two-sheets of material, at least one of such sheets including a component of a given width adapted to have a visible image formed therein, said apparatus comprising:

a pair of spreader elements each having opposed ends and each of which has a surface at least equal in length to such given width of such component; and

means for pivotally connecting said elements together for movement between a first position wherein said surfaces are disposed in juxtaposition and a second position wherein said surfaces are removed from juxtaposition and for resiliently urging said elements towards one another when in their said first position to form a pressure-generating gap between said surfaces thereof through which such sheets are movable to first effect the rupture of such pod of processing fluid and then to effect the spreading of such fluid in a layer therebetween, said surface of at least one of said spreader elements being configured to present, at least when said elements are disposed in their said first position, a relatively small recessed portion constituting a discontinuity of said surface of said one spreader element adjacent each end thereof, whereby the thickness of such layer of fluid as initially spread by said elements adjacent said relatively small recessed portions is greater than that of the remaining portions of such layer of fluid as initially spread by said elements.

10. The invention of claim 9 wherein said surfaces are substantially parallel, when said elements are disposed in their said first position, except. for those sections thereof adjacent said relatively small recessed portions.

1 1. Apparatus for rupturing a pod of processing fluid and for spreading such processing fluid as a layer between two sheets-of material, at least one of such sheets including a component of a given width adapted to have a visible image formed therein, said apparatus comprising:

a pair of spreader elements each having opposed ends and each of which has a surface at least equal in length to such given width of such component, at least one of said elements being formed of a substantially resiliently flexible material; and

means for pivotally connecting said elements together for movement between a first position wherein said surfaces are disposed in juxtaposition and a second position wherein said surfaces are removed from juxtaposition and for resiliently urging said elements towards one another when in their said first position to form a pressure-generating gap between said surfaces thereof through which such sheets are movable to first effect the rupture of such pod of processing fluid and then to effect the spreading of such fluid in a layer therebetween, said surface of said resiliently flexible element being configured to present a recessed portion extending substantially thereacross when tion is greater than that of the remaining portions of such layer of fluid spread by said elements. 12. Apparatus for rupturing a pod of processing fluid and for spreading such processing fluid as a layer between two sheets of material, at least one of such sheets including a component of a given width adapted to have a visible image formed therein, said apparatus comprising:

a pair of spreader elements each having opposed ends and each of which has a surface at least equal in length to such given width of such component, at least one of said elements being formed of a substantially resiliently flexible material; and

means for pivotally connecting said elements together for movement between a first position wherein said surfaces are disposed in juxtaposition and a second position wherein said surfaces are removed from juxtaposition and for resiliently urging said elements towards one another when in their said first position to form a pressure-generating gap between said surfaces thereof through which such sheets are movable to first effect the rupture of such pod of processing fluid and then to effect the spreading of such fluid in a layer therebetween, said surface of said resiliently flexible element being configured to present a recessed portion extending substantially thereacross when said elements are in their said second position, said pivotal connecting means including means for transferring a force to said resiliently flexible element intermediate the ends of its said surface and a resiliently flexible member acting against said force transferring means at least when said elements are disposed in their said first position causing said surface of said resiliently flexible element to deform at such times to provide one relatively small recessed portion adjacent each vsaid end thereof, whereby the thickness of such layer of fluid spread by said elements adjacent said relatively small recessed portions is greater than that of the remaining portions of such layer of fluid spread by said elements.

13. The invention of claim 12 wherein said resiliently flexible member comprises a rod adjacent the ends of said elements are in their said second position, said which Said elements are pivotally mountedpivotal connecting means including means for ex- 

1. Apparatus for rupturing a pod of processing fluid and for spreading such processing fluid as a layer between two sheets of material responsive to relative motion being effected between said apparatus and such sheets lengthwise of such sheets, at least one of such sheets including a component adapted to have a visible image formed in a section thereof having a given width, said apparatus comprising: a pair of spreader elements each having a sheet contacting surface extending a distance at least equal in length to such section of such component; means for mounting said spreader elements with their said sheet contacting surfaces in juxtaposition and disposed to exert a compressive force on such sheets over such section of such component as they are progressively drawn lengthwise therebetween in superposed relationship to first effect the rupture of such pod of processing fluid and then to effect the spreading of such fluid in a layer between such sheets; and means on at least one of said spreader elements for increasing the thickness of such layer of fluid spread between such sheets by said spreader elements along at least one longitudinal portion of such section of such component spaced from the longitudinal centerline of such component section and adjacent one longitudinal edge thereof, said last mentioned means including a recess in, and constituting a discontinuity of, said surface of said one spreader element adjacent such one longitudinal portion of such component section.
 2. The invention of claim 1 wherein said recess comprises a concavity.
 3. The invention of claim 1 wherein said last mentioned means includes a pair of recesses provided in, and constituting discontinuities of, said surface of said one spreader element respectively formed on said one spreader element spaced from the longitudinal centerline of such section of sUch component and positioned adjacent the longitudinal edges of such section of such component as such sheets are moved relative to said spreader elements.
 4. The invention of claim 1 wherein such one sheet is relatively flexible with respect to the other of such sheets and said recess is formed in said surface of said spreader element adapted to engage said one sheet.
 5. The invention of claim 1 wherein said spreader elements are of the substantially rigid non-rolling type.
 6. The invention of claim 1 wherein at least one of said spreader elements comprises a roller.
 7. The invention of claim 1 wherein said juxtaposed surfaces are substantially parallel except for the portions thereof adjacent said fluid thickness increasing means.
 8. Apparatus for rupturing a pod of processing fluid and for spreading such processing fluid as a layer between two sheets of material responsive to relative motion being effected between said apparatus and such sheets lengthwise of such sheets, at least one of such sheets including a component adapted to have a visible image formed in a section thereof having a given width, said apparatus comprising: a pair of spreader elements each having opposed ends and a sheet contacting surface extending a distance at least equal in length to such section of such component; means for mounting said spreader elements with their said sheet contacting surfaces in juxtaposition and disposed to exert a compressive force on such sheets over such section of such component as they are progressively drawn lengthwise therebetween in superposed relationship to first effect the rupture of such pod of processing fluid and then to effect the spreading of such fluid in a layer between such sheets; and means on at least one of said spreader elements for increasing the thickness of such layer of fluid spread between such sheets by said spreader elements along at least one longitudinal portion of such section of such component, said last mentioned means including a recess in, and constituting a discontinuity of, said surface of said one spreader element adjacent such one longitudinal portion of such component section and entirely positioned between the ends of the portion of said surface of said one spreader element adapted to extend across such section of such one sheet as such sheets pass between said spreader elements.
 9. Apparatus for rupturing a pod of processing fluid and for spreading such processing fluid as a layer between two sheets of material, at least one of such sheets including a component of a given width adapted to have a visible image formed therein, said apparatus comprising: a pair of spreader elements each having opposed ends and each of which has a surface at least equal in length to such given width of such component; and means for pivotally connecting said elements together for movement between a first position wherein said surfaces are disposed in juxtaposition and a second position wherein said surfaces are removed from juxtaposition and for resiliently urging said elements towards one another when in their said first position to form a pressure-generating gap between said surfaces thereof through which such sheets are movable to first effect the rupture of such pod of processing fluid and then to effect the spreading of such fluid in a layer therebetween, said surface of at least one of said spreader elements being configured to present, at least when said elements are disposed in their said first position, a relatively small recessed portion constituting a discontinuity of said surface of said one spreader element adjacent each end thereof, whereby the thickness of such layer of fluid as initially spread by said elements adjacent said relatively small recessed portions is greater than that of the remaining portions of such layer of fluid as initially spread by said elements.
 10. The invention of claim 9 wherein said surfaces are substantially parallel, when said elements are disposed in their said first position, except for those sections thereof adjacent said relatively small recessed portions.
 11. Apparatus for rupturing a pod of processing fluid and for spreading such processing fluid as a layer between two sheets of material, at least one of such sheets including a component of a given width adapted to have a visible image formed therein, said apparatus comprising: a pair of spreader elements each having opposed ends and each of which has a surface at least equal in length to such given width of such component, at least one of said elements being formed of a substantially resiliently flexible material; and means for pivotally connecting said elements together for movement between a first position wherein said surfaces are disposed in juxtaposition and a second position wherein said surfaces are removed from juxtaposition and for resiliently urging said elements towards one another when in their said first position to form a pressure-generating gap between said surfaces thereof through which such sheets are movable to first effect the rupture of such pod of processing fluid and then to effect the spreading of such fluid in a layer therebetween, said surface of said resiliently flexible element being configured to present a recessed portion extending substantially thereacross when said elements are in their said second position, said pivotal connecting means including means for exerting a force against said resiliently flexible element intermediate the ends of its said surface urging said resiliently flexible element towards the other of said elements when said elements are in their said first position causing said surface of said resiliently flexible element to deform at such times to provide one relatively small recessed portion adjacent each said end thereof whereby the thickness of such layer of fluid spread by said elements adjacent said relatively small recessed portion is greater than that of the remaining portions of such layer of fluid spread by said elements.
 12. Apparatus for rupturing a pod of processing fluid and for spreading such processing fluid as a layer between two sheets of material, at least one of such sheets including a component of a given width adapted to have a visible image formed therein, said apparatus comprising: a pair of spreader elements each having opposed ends and each of which has a surface at least equal in length to such given width of such component, at least one of said elements being formed of a substantially resiliently flexible material; and means for pivotally connecting said elements together for movement between a first position wherein said surfaces are disposed in juxtaposition and a second position wherein said surfaces are removed from juxtaposition and for resiliently urging said elements towards one another when in their said first position to form a pressure-generating gap between said surfaces thereof through which such sheets are movable to first effect the rupture of such pod of processing fluid and then to effect the spreading of such fluid in a layer therebetween, said surface of said resiliently flexible element being configured to present a recessed portion extending substantially thereacross when said elements are in their said second position, said pivotal connecting means including means for transferring a force to said resiliently flexible element intermediate the ends of its said surface and a resiliently flexible member acting against said force transferring means at least when said elements are disposed in their said first position causing said surface of said resiliently flexible element to deform at such times to provide one relatively small recessed portion adjacent each said end thereof, whereby the thickness of such layer of fluid spread by said elements adjacent said relatively small recessed portions is greater than that of the remaining portions of such layer of fluid spread by said elements.
 13. The invention of claim 12 wherein said resiliently flexible member compriSes a rod adjacent the ends of which said elements are pivotally mounted. 